The invention relates to a device for grasping an object from a remote location and, more particularly, to an end effector device for the end of a remotely controlled mechanical manipulator arm of the type used in robotic manufacturing and assembly operations and various space exploration programs whereby an object may be grasped by insertion of the device into an open part of the object or, in another but similar configuration of the device, by insertion of a long cylindrical part of the object into the device.
Prior devices have been developed for grasping objects and performing general work in these applications which have typically included a set of opposed jaws or fingers which are movable towards and away from each other such as shown in U.S. Pat. No. 3,268,091. These devices apply considerable point-contact loads to an object, however, and with the increasing use of fragile thin frame and composite structures, these jaw-type end effectors cannot be utilized without substantial risk of damage to the object being handled or must be equipped with complex sensors to limit the loads applied to the object.
It has also been known to pick up articles having an opening such as bottles with inflatable devices. However, these devices do not readily lend themselves to the structures and problems involved in space applications.
A pneumatic inflatable end effector, U.S. Pat. No. 4,273,508, has been designed to handle thin frame structures in space by utilizing a balloon stretched over a telescoping central tube. While similar in nature, this system lacks the rigidity and locational repeatability required for many robotic and teleoperated handling operations, is of a more complex mechanical nature, and is inherently more fragile than the device described herein.
Of importance to note also is that while prior inflatable grasping devices grasp objects by being placed within an opening in the object, one embodiment of the device described herein has the capability of grasping the outer surface of an object, efficiently handling such items as rods, pins, and other long slender objects which do not have an opening.